Results 



The regression lines for the male fat volume for 

 the two years intersect and are not significantly dif- 

 ferent (Table 1). The results of the analysis of 

 covariance for fat volume of females are highly 

 significant (Table 1). Females had significantly 

 higher fat volumes in 1980 for both months (Fig. 

 1). 



The comparisons of gonad volumes produced 

 highly significant results in December for both 

 sexes, and for females in September (Table 2). 

 Female gonad volumes were higher in 1980 during 

 December and lines intersected in September (Fig. 

 2). Male gonad volumes were significantly higher in 

 December 1983 than in December 1980. 



The seasonality of gonad development was similar 

 in the two years, but appeared to be delayed in 1983. 



Table 1.— Results of analysis of covariance of fat volumes of yellowtail rockfish regressed 

 on length. Observations were transformed to natural logarithms for the analysis. 



* "Significant at 99% level of confidence. 



3.5 

 3.0 



E 2.5 

 i 







E 



•2 2.0 

 o 



> 



5 1.5 



1.0 



0.5 



a a Sep. 1980 



a- -* Sep. 1983 



• • Dec. 1980 



•---• Dec. 1983 



_L 



_L 



5.9 6.0 6.1 6.2 6.3 

 In (total length-mm) 



Figure 1.— Relationships between In (visceral fat volume) and In 

 (total length) for female yellowtail rockfish in 1980 and 1983. 



Males were 50% maturing and 50% resting in 

 September 1980, and 100% resting during Decem- 

 ber. In 1983 males were 100% maturing during 

 September, and 8% maturing and 92% resting dur- 

 ing December. Females were 35% maturing and 

 65% resting in September 1980, and 83% maturing 

 and 17% resting in December. In 1983 females were 

 100% maturing during September, and 97% matur- 

 ing and 2% resting during December. Data on 

 season or parturition for 1981-84 (Table 3) indicate 

 that parturition was delayed in 1983 and 1984 com- 

 pared with 1981 and 1982. 



Discussion 



The results tend to agree with expectations. 

 Female fat volumes were lower in 1983 than in 1980, 

 which is in agreement with the impressions of fisher- 

 men and the expectation that El Nino would pro- 

 duce relatively poor feeding conditions and conse- 

 quently result in thin fish. 



Table 2.— Results of analysis of covariance of gonad volumes of yellowtail rockfish regressed 

 on length. Observations were transformed to natural logarithms for the analysis. 



'•Significant at 99% level of confidence. 

 'Significant at 95% level of confidence. 



744 



